Step device for vehicle

ABSTRACT

A step device for a vehicle includes: a movable step supported under a door opening; a coupling member that, in a state of being supported by a sliding door, engages with the movable step to move the movable step in a vehicle width direction in conjunction with opening and closing of the sliding door; a support arm that has a first pivot-joint point relative to a vehicle body and a second pivot-joint point relative to the movable step, and supports the movable step toward an upper side; and a pressure bearing member that is provided at a position between the first pivot-joint point and the second pivot-joint point and bears the load of the support arm by coming into sliding contact with the support arm.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Japanese Patent Application No.2019-164026 filed on Sep. 9, 2019, incorporated herein by reference inits entirety.

BACKGROUND 1. Technical Field

The present disclosure relates to a step device for a vehicle.

2. Description of Related Art

There are step devices for vehicles in which a movable step providedunder a door opening is moved in a vehicle width direction inconjunction with opening and closing of a sliding door. For example, inthe step device described in Japanese Patent Application Publication No.2007-269086, a movable step is coupled to a sliding door through a guidemember that is provided on a lower surface of the movable step and acoupling member that has a sliding member guided by the guide member.Thus, the movable step is moved to a deployed position on an outer sidein a vehicle width direction in conjunction with the sliding door as thesliding door opens toward a vehicle rear side while shifting toward theouter side in the vehicle width direction, and is moved to a retractedposition on an inner side in the vehicle width direction in conjunctionwith the sliding door as the sliding door closes toward a vehicle frontside while shifting toward the inner side in the vehicle widthdirection.

In the step device shown in this example, the movable step is supportedabove a pair of parallel links that serve as support arms. These supportarms are turned to move the movable step in the vehicle width direction.

SUMMARY

In a configuration in which support arms like those described above areused, the load of the movable step tends to concentrate at a pivot-jointpoint of each support arm relative to the vehicle body and a pivot-jointpoint of each support arm relative to the movable step. If the number ofthe support arms is to be increased to three or larger to mitigate theload concentration, the lengths of these support arms need to be exactlycontrolled such that the turning support arms do not interfere with oneanother. This makes it difficult to enhance the supporting rigidity ofthe support arms, which is where there is still room for improvement.

The present disclosure provides a step device for a vehicle in whichhigher supporting rigidity can be secured.

A step device for a vehicle according to an aspect of the presentdisclosure includes a movable step supported under a door opening; acoupling member that, in a state of being supported by a sliding doorthat opens and closes in a vehicle front-rear direction with a shiftingzone in a vehicle width direction, engages with the movable step to movethe movable step in the vehicle width direction in conjunction withopening and closing of the sliding door; a support arm that has a firstpivot-joint point relative to a vehicle body and a second pivot-jointpoint relative to the movable step, and supports the movable step towardan upper side; and a pressure bearing member that is provided at aposition between the first pivot-joint point and the second pivot-jointpoint and bears the load of the support arm by coming into slidingcontact with the support arm.

In this aspect, the pressure bearing member supports the load of thesupport arm, so that the load of the movable step supported by thesupport arm is less likely to concentrate at the first pivot-joint pointof the support arm relative to the vehicle body and the secondpivot-joint point of the support arm relative to the movable step. Thus,higher supporting rigidity can be secured.

In the above aspect, the support arm may have a support bracket that isfixed to the vehicle body to form the first pivot-joint point, and thepressure bearing member may be provided on the support bracket.

In this aspect, the pressure bearing member provided on the supportbracket supports the load of the support arm, so that the load of themovable step supported by the support arm is less likely to concentrateat the first pivot-joint point of the support arm relative to thevehicle body. Thus, higher supporting rigidity can be secured.

In the above aspect, the step device may further include a holdingmember that is fixed to the movable step so as to hold, together withthe movable step, the support arm at the second pivot-joint point, andthe pressure bearing member may be provided on the holding member.

In this configuration, the holding member holds, together with themovable step, the support arm, which increases the supporting rigidityof the support arm at the second pivot-joint point thereof relative tothe movable step. Further, the pressure bearing member provided on theholding member supports the load of the support arm, so that the load ofthe movable step is less likely to concentrate at the second pivot-jointpoint. Thus, higher supporting rigidity can be secured.

In the above aspect, the pressure bearing member may have a slidingcontact surface that extends in a direction intersecting the supportarm. In this configuration, the pressure bearing member can be stablybrought into sliding contact with the support arm that turns around thefirst pivot-joint point and the second pivot-joint point as fulcrums.Thus, higher supporting rigidity can be secured.

In the above configuration, the pressure bearing member may be made of aresin having a shock absorbing property and a self-lubricating property.This configuration makes it possible to ensure smooth turning of thesupport arm by absorbing a shock load of the movable step transmitted tothe support arm and, at the same time, to reduce the sliding sound ofthe support arm.

In the above configuration, a ridge that extends in a directionintersecting the support arm and comes into sliding contact with thesupport arm may be provided on a lower surface of the movable step.Further, in the above configuration, the movable step may include amovable base to which the support arm is coupled, and a resin cover thatis fixed to the movable base to be a step surface. The ridge may beprovided on a lower surface of the resin cover and protrude toward alower surface side of the movable step through a hole provided in themovable base.

In this configuration, the ridge provided on the movable step comes intosliding contact with the support arm located under the ridge, so thatthe load of the movable step can be stably supported. Further, as theridge extends in a direction intersecting the support arm, the area ofcontact between the ridge and the support arm can be reduced. Thus, itis possible to ensure smooth turning of the support arm and, at the sametime, to reduce the sliding sound of the support arm.

In the above aspect, the support arm may include two main arms that areprovided at positions apart from each other in the vehicle front-reardirection, and a sub-arm that has a joint at which the sub-arm isbendable and that is provided at a position apart from each of the mainarms.

In this configuration, the bent shape of the sub-arm having a jointchanges such that the turning sub-arm does not interfere with eachturning main arm. Thus, the number of the support arms can be increasedto enhance the supporting rigidity for the movable step, while smoothmovement of the movable step is ensured.

In the above configuration, the sub-arm may be provided between the mainarms. In this configuration, the two main arms can be disposed a greaterdistance apart from each other in the vehicle front-rear direction.Thus, the movable step can be more stably supported.

In the above aspect, the step device may further include a stopper thatrestricts a movable range of the movable step by coming into contactwith the support arm. In this configuration, the movable step supportedby the support arm can be appropriately moved in the vehicle widthdirection between the retracted position and the deployed position.Thus, the quality of the movable step can be enhanced.

The present disclosure can secure higher supporting rigidity.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, advantages, and technical and industrial significance ofexemplary embodiments of the disclosure will be described below withreference to the accompanying drawings, in which like signs denote likeelements, and wherein:

FIG. 1 is a perspective view of a vehicle showing a sliding door and astep device provided at a door opening;

FIG. 2 is a side view of the vehicle showing the sliding door and thestep device provided at the door opening;

FIG. 3A is a plan view showing the sliding door that opens and closes ina vehicle front-rear direction while shifting in a vehicle widthdirection, and the route of movement of the sliding door;

FIG. 3B is a plan view showing the sliding door that opens and closes inthe vehicle front-rear direction while shifting in the vehicle widthdirection, and the route of movement of the sliding door;

FIG. 4A is a plan view of the step device;

FIG. 4B is a plan view of the step device;

FIG. 5A is a plan view of the step device;

FIG. 5B is a plan view of the step device;

FIG. 6 is a sectional view of the step device;

FIG. 7 is a bottom view of the step device;

FIG. 8 is an exploded perspective view of a movable step;

FIG. 9 is a sectional view showing a guide roller unit as a couplingmember that engages with a guide rail provided on the movable step;

FIG. 10 is an exploded perspective view of the guide roller unit;

FIG. 11 is a view illustrating free running zones set for the guiderail;

FIG. 12 is a view illustrating an action in a closing-side free runningzone during opening of the sliding door;

FIG. 13 is a view illustrating an action in a closing-side free runningzone during closing of the sliding door;

FIG. 14 is a view illustrating an action in an opening-side free runningzone;

FIG. 15 is an exploded perspective view of a sub-step;

FIG. 16A is a plan view of the sub-step;

FIG. 16B is a sectional view of the sub-step;

FIG. 16C is a sectional view of the sub-step;

FIG. 17A is a plan view of support arms that support the movable step;

FIG. 17B is a plan view of the support arms that support the movablestep;

FIG. 18 is a perspective view of the movable step and support bracketsthat are coupled together through the support arms;

FIG. 19 is an exploded perspective view of the support arms and thesupport brackets;

FIG. 20 is a plan view around a first joint point of the support armrelative to the support bracket;

FIG. 21 is a sectional view around the first joint point of the supportarm relative to the support bracket;

FIG. 22A is a side view of a pressure bearing member provided on thesupport bracket;

FIG. 22B is a bottom view of the pressure bearing member provided on thesupport bracket;

FIG. 23 is a bottom view around a second joint point of the support armrelative to the movable step;

FIG. 24 is a sectional view around the second joint point of the supportarm relative to the movable step;

FIG. 25A is a bottom view of the pressure bearing member provided on aholding member that, together with the movable step, holds the supportarm;

FIG. 25B is a side view of the pressure bearing member provided on theholding member that, together with the movable step, holds the supportarm;

FIG. 26A is a bottom view of a resin cover constituting a part of themovable step;

FIG. 26B is a bottom view of a movable base constituting a part of themovable step;

FIG. 27 is a sectional view of the step device in a state where themovable step is in a retracted position;

FIG. 28 is a perspective view of a cover member, a seal member, and aretaining member;

FIG. 29A is a plan view of the cover member;

FIG. 29B is a plan view of the cover member disposed under the supportarms and the support brackets;

FIG. 30 is a sectional view of the step device in the state where themovable step is in the retracted position;

FIG. 31 is a perspective view of the cover member with the seal memberfixed at a leading end of a peripheral wall;

FIG. 32 is a perspective view of the cover member with the seal memberfixed at the leading end of the peripheral wall;

FIG. 33 is a perspective view of the cover member with the seal memberfixed at the leading end of the peripheral wall;

FIG. 34 is a sectional view of a vehicle front-side peripheral wall partthat is provided at a front end portion of the cover member;

FIG. 35A is a side view of a guide roller unit;

FIG. 35B is a side view of the guide roller unit;

FIG. 36 is a view illustrating actions of inserting and removing theguide roller unit into and from a guide rail;

FIG. 37 is a bottom view of the guide rail showing a notch provided at alongitudinal end portion on a vehicle rear side;

FIG. 38 is a bottom view of the guide rail showing a notch provided at acorner of a curved portion;

FIG. 39A is an enlarged view of the retaining member provided on thebottom wall of the cover member;

FIG. 39B is an enlarged view of the retaining member provided on thebottom wall of the cover member;

FIG. 40 is a view illustrating another example of movement of themovable step in the vehicle width direction in conjunction with openingand closing of the sliding door; and

FIG. 41 is a sectional view of a movable step and a sub-step showinganother example of a stopper structure.

DETAILED DESCRIPTION OF EMBODIMENTS

One embodiment relating to a step device for a vehicle will be describedbelow in accordance with the drawings. As shown in FIG. 1, a vehicle 1of this embodiment includes a sliding door 4 that can move in a vehiclefront-rear direction (a left-right direction in FIG. 1) so as to openand close a door opening 3 provided in a side surface of a vehicle body2.

Specifically, as shown in FIG. 2, the vehicle 1 of the embodiment has aplurality of guide rails 10 that is provided on the side surface of thevehicle body 2 and extends in the vehicle front-rear direction. Inparticular, the vehicle 1 of the embodiment is provided with a lowerrail 11 disposed at a lower edge of the door opening 3, a center rail 12disposed on a rear side of the door opening 3, and an upper rail 13disposed at an upper edge of the door opening 3. Further, each of theseguide rails 10 has a guide roller unit 20 coupled thereto that can slidealong an extension direction of the guide rail 10. In the vehicle 1 ofthe embodiment, the sliding door 4 is supported by the vehicle body 2through the guide roller units 20 such that the sliding door 4 can openand close along the guide rails 10 extending in the vehicle front-reardirection.

As shown in FIG. 3A and FIG. 3B, each of the guide rails 10 of theembodiment has, at a longitudinal end portion 10 f on a vehicle frontside, i.e., an end portion on a side where the sliding door 4 is fullyclosed, a curved portion 30 that curves toward an inner side in thevehicle width direction (the upper side in FIG. 3A and FIG. 3B) whileextending from a vehicle rear side toward the vehicle front side. Forthe convenience of illustration, the lower rail 11 and a lower rollerunit 21 are shown in FIG. 3A and the center rail 12 and a center rollerunit 22 are shown in FIG. 3B, while the upper rail 13 and an upperroller unit 23 are not shown. The sliding door 4 of the embodiment opensand closes in the vehicle front-rear direction while shifting in thevehicle width direction in a state of being guided by the curvedportions 30 provided in the guide rails 10.

When the sliding door 4 of the embodiment is in a fully closed positionPc, an outer surface 4 a thereof is substantially flush with a sidesurface 2 a of the vehicle body 2. When opening from the fully closedposition Pc, the sliding door 4 moves toward the vehicle rear side whileshifting toward the outer side in the vehicle width direction. A routeof movement R of the sliding door 4 has, on the side of the fully closedposition Pc, a width-direction shifting zone Re in which the slidingdoor 4 shifts in the vehicle width direction. In FIG. 3A and FIG. 3B,the long dashed short dashed line represents the track of the openingand closing sliding door 4, particularly a front end portion thereof.Thus, in the vehicle 1 of the embodiment, the sliding door 4 does notinterfere with the vehicle body 2 when opening and closing.

As shown in FIG. 2, the vehicle 1 of the embodiment is provided with apower sliding door device 31 that opens and closes the sliding door 4using a motor 31 m as a driving source. An occupant of the vehicle 1 canopen and close the sliding door 4 not only by manual operation but alsoby operating a door handle (not shown), an operation switch providedinside a vehicle cabin, or a portable device. The power sliding doordevice 31 monitors changes in driving power required to open and closethe sliding door 4, i.e., a force required to open and close the slidingdoor 4, based on rotation of the motor 31 m, an amount of currentapplied thereto, etc. Thus, the power sliding door device 31 functionsas a catching detection device 32 that detects whether any object iscaught in the sliding door 4.

In particular, the catching detection device 32 of the embodimentdetermines that an object is caught in the sliding door 4 when, forexample, the amount of current to the motor 31 m increases beyond apredetermined threshold value while the sliding door 4 is driven to openor close. To release an object caught in the sliding door 4 or preventthe sliding door 4 from catching an object, the power sliding doordevice 31 of the embodiment executes driving control involving, forexample, driving the sliding door 4, which is being driven to close,reversely in an opening direction or stopping the sliding door 4 beingdriven to open.

As shown in FIG. 1 and FIG. 2, the vehicle 1 of the embodiment isprovided with a step device 41 that deploys a step member 40 serving asa step under the door opening 3 to be used by an occupant who gets in orout of the vehicle 1.

Specifically, as shown in FIG. 4A, FIG. 4B, FIG. 5A, FIG. 5B, and FIG.6, the step device 41 of the embodiment includes a movable step 42 thatis supported under the door opening 3 in a state of being movable in thevehicle width direction, and a sub-step 43 that is disposed under thedoor opening 3, along with the movable step 42, in a state of beingfixed to the vehicle body 2. The vehicle width direction corresponds toan up-down direction in FIG. 4A, FIG. 4B, FIG. 5A, and FIG. 5B and aleft-right direction in FIG. 6.

In particular, as shown in FIG. 4A to FIG. 7, the step device 41 of theembodiment includes a plurality of support arms 44 that is turnablycoupled to both the vehicle body 2 and the movable step 42. By beingsupported by the support arms 44, the movable step 42 of the embodimentmoves under the sub-step 43 in the vehicle width direction whilemaintaining a substantially horizontal posture.

More specifically, the step device 41 of the embodiment includes aplurality of support brackets 45 that is fixed to a lower surface 2 b ofthe vehicle body 2. The support arms 44 of the embodiment are coupled tothe vehicle body 2 through the support brackets 45. In the step device41 of the embodiment, each support arm 44 turns in a substantiallyhorizontal direction around, as a fulcrum, a first pivot-joint point M1relative to the vehicle body 2 that is formed by this coupling.

As shown in FIG. 6 to FIG. 8, the movable step 42 of the embodimentincludes a substantially flat-plate-shaped movable base 47 that hascoupling portions 46 for the respective support arms 44, and a resincover 48 that is fixed to the movable base 47 in a state of covering anupper surface 47 a of the movable base 47. In the movable step 42 of theembodiment, an upper surface 48 a of the resin cover 48 constitutes astep surface S1 on which a user places his or her foot. The couplingportions 46 for the respective support arms 44 are formed as insertionholes 49 extending through the movable base 47 in the up-down direction.Thus, in the step device 41 of the embodiment, each support arm 44 turnsrelatively to the movable step 42 around, as a fulcrum, a secondpivot-joint point M2 that is formed using the coupling portion 46, whilemaintaining a substantially horizontal posture of the movable step 42.

In the movable step 42 of the embodiment, the movable base 47 is formedusing metal. The upper surface 48 a of the resin cover 48 hasdepressions and protrusions to prevent slipping. Thus, the step device41 of the embodiment allows an occupant having placed his or her foot onthe movable step 42 to safely step onto the step surface S1.

As shown in FIG. 4A to FIG. 9, the movable step 42 of the embodimentincludes a guide rail 50 that is provided on a lower surface 42 bthereof and extends in a longitudinal direction. The step device 41 ofthe embodiment includes a guide roller unit 52 as a coupling memberthat, in a state of being supported by the sliding door 4, engages withthe guide rail 50 of the movable step 42.

As shown in FIG. 6 to FIG. 8, the guide rail 50 of the embodiment isformed by fixing, to the movable base 47 constituting the lower surface42 b of the movable step 42, rail members 53, 54 that extend in thelongitudinal direction of the movable base 47. In particular, themovable base 47 of the embodiment includes a peripheral wall 55 that isformed by folding down a peripheral edge portion of the movable base 47on the outer side in the vehicle width direction toward the side of thelower surface 47 b and extends in the longitudinal direction. The railmembers 53, 54 are integrally fixed to the lower surface 47 b of themovable base 47 so as to be parallel to the peripheral wall 55.

As shown in FIG. 6 and FIG. 9, in the guide rail 50 of the embodiment,the peripheral wall 55 of the movable base 47 constitutes a side wall 57on the outer side in the vehicle width direction, and the rail members53, 54 facing the peripheral wall 55 in the vehicle width directionconstitute a side wall 58 on the inner side in the vehicle widthdirection. The side wall 58 on the inner side in the vehicle widthdirection is provided with a fall prevention flange 59 that is formed bybending a lower end portion of the side wall 58 so as to extend towardthe side wall 57 on the outer side in the vehicle width direction. Inthe step device 41 of the embodiment, the fall prevention flange 59 isprovided in the rail member 53 constituting a part of the side wall 58(see FIG. 8). The guide roller unit 52 of the embodiment includes aguide roller 60 that is disposed between side walls 57, 58 of the guiderail 50 facing each other.

In particular, as shown in FIG. 6, FIG. 9, and FIG. 10, the guide rollerunit 52 of the embodiment includes a fixed member 61 that is fixed tothe sliding door 4 in a state of extending in the up-down direction, andan arm member 62 that extends toward the inner side in the vehicle widthdirection in a state of being coupled to a lower end of the fixed member61. A support shaft 60 x extending in the up-down direction is providedat a leading end of the arm member 62. The support shaft 60 x of theguide roller unit 52 of the embodiment rotatably supports the guideroller 60.

The guide roller unit 52 of the embodiment moves integrally with thesliding door 4 based on opening and closing of the sliding door 4. Theguide roller 60 disposed inside the guide rail 50 also moves in thevehicle front-rear direction according to the direction of movement ofthe sliding door 4. In the guide rail 50 of the embodiment, the fallprevention flange 59 provided at the lower end of the side wall 58prevents the guide roller 60 located between the side walls 57, 58 fromcoming off. The guide roller unit 52 of the embodiment causes themovable step 42 provided with the guide rail 50 to move in the vehiclewidth direction as the guide roller 60 comes into sliding contact withand presses the side wall 57 of the guide rail 50 located on the outerside in the vehicle width direction or the side wall 58 of the guiderail 50 located on the inner side in the vehicle width direction.

In particular, the guide roller unit 52 of the embodiment causes themovable step 42 to move toward the outer side in the vehicle widthdirection as the guide roller 60 comes into sliding contact with theside wall 57 of the guide rail 50 located on the outer side in thevehicle width direction and, while pressing the side wall 57, movesinside the guide rail 50 in a direction toward the vehicle rear sidethat is the opening direction of the sliding door 4. The guide rollerunit 52 causes the movable step 42 to move toward the inner side in thevehicle width direction as the guide roller 60 comes into slidingcontact with the side wall 58 of the guide rail 50 located on the innerside in the vehicle width direction and, while pressing the side wall58, moves inside the guide rail 50 in a direction toward the vehiclefront side that is the closing direction of the sliding door 4. Thus, inthe step device 41 of the embodiment, the movable step 42 is moved froma retracted position P1 to a deployed position P2 in conjunction withopening of the sliding door 4, and is moved from the deployed positionP2 to the retracted position P1 in conjunction with closing of thesliding door 4 (see FIG. 4A, FIG. 4B, FIG. 5A, and FIG. 5B).

More specifically, as shown in FIG. 7 and FIG. 11, the guide rail 50 ofthe embodiment includes, at a longitudinal end portion 50 f on thevehicle front side, i.e., an end portion on the side where the slidingdoor 4 is fully closed, a curved portion 70 that curves toward the innerside in the vehicle width direction while extending from the vehiclerear side toward the vehicle front side, like the curved portion 30provided in each guide rail 10 of the sliding door 4. The inner side inthe vehicle width direction corresponds to the lower side in FIG. 7 andthe upper side in FIG. 11. Thus, in the step device 41 of theembodiment, the movable step 42 can be gently moved in the vehicle widthdirection as the guide roller 60 moves smoothly inside the guide rail 50based on opening or closing of the sliding door 4.

Free Running Zones

Next, free running zones set for the guide rail 50 of the embodimentwill be described. As shown in FIG. 11, the guide rail 50 of theembodiment has two free running zones, one near the longitudinal endportion 50 f on the vehicle front side and the other on the vehicle rearside of the curved portion 70. In these free running zones, the guideroller 60 serving as an engaging part of the coupling member that movesintegrally with the sliding door 4 does not press the side walls 57, 58located on both sides of the guide roller 60 in the vehicle widthdirection. In particular, in the guide rail 50 of the embodiment, aterminal end region Lc on a closing side including a terminal endposition Xc at which the guide roller 60 is located when the slidingdoor 4 is fully closed constitutes a closing-side free running zone ac.In the guide rail 50 of the embodiment, a moving region Lo on an openingside from a moving position X2 at which the guide roller 60 is locatedwhen the movable step 42 reaches the deployed position P2 constitutes anopening-side free running zone αo.

In the step device 41 of the embodiment, when the guide roller 60 movesin an engaging zone β located between the closing-side free running zoneαc and the opening-side free running zone αo, the movable step 42 movesin the vehicle width direction in conjunction with opening and closingof the sliding door 4. Thus, the movable step 42 of the embodimentreaches the deployed position P2 from the retracted position P1 by anamount of shift W2 in the vehicle width direction that is smaller thanan amount of shift W1 in the vehicle width direction that the slidingdoor 4 undergoes while opening or closing (W1>W2).

Specifically, as shown in FIG. 9, in the guide rail 50 of theembodiment, the interval between the side walls 57, 58 facing each otherin the vehicle width direction, i.e., a rail width Dw, is set to a valuelarger than a diameter Dr of the guide roller 60 (Dw>Dr). Theclosing-side free running zone αc of the embodiment constitutes anon-sliding-contact zone γ in which the guide roller 60 moving in theclosing-side free running zone αc in the vehicle front-rear directionmoves inside the guide rail 50 in the vehicle width direction, whileshifting in a rail width direction without coming into sliding contactwith the side walls 57, 58.

More specifically, as shown in FIG. 12 and FIG. 13, in the closing-sidefree running zone αc, a gradient of change θ1 of the side wall 57located on the outer side of the guide roller 60 in the vehicle widthdirection is set to be smaller than a gradient of change θr set for atrack of movement Qr of the guide roller 60 that moves inside the guiderail 50 in the vehicle front-rear direction while moving in the vehiclewidth direction (θr>θ1). The lower side and the left side in FIG. 12 andFIG. 13 correspond to the outer side in the vehicle width direction andthe vehicle front side, respectively. A gradient of change θ2 of theside wall 58 located on the inner side of the guide roller 60 in thevehicle width direction is set to be larger than the gradient of changeθr set for the track of movement Qr of the guide roller 60 (θr<θ2).

Thus, as shown in FIG. 12, in the guide rail 50 of the embodiment, theclosing-side free running zone αc as the non-sliding-contact zone γconstitutes a zone in which, when the sliding door 4 opens, the guideroller 60 moving inside the guide rail 50 toward the vehicle rear sideshifts in the rail width direction so as to be gradually closer to theside wall 57 located on the outer side of the guide roller 60 in thevehicle width direction. Thus, in the guide rail 50 of the embodiment,the guide roller 60 having passed through the closing-side free runningzone αc comes quickly into sliding contact with the side wall 57 locatedon the outer side of the guide roller 60 in the vehicle width directionand presses the side wall 57.

Further, as shown in FIG. 13, the closing-side free running zone αc asthe non-sliding-contact zone γ constitutes a zone in which, when thesliding door 4 closes, the guide roller 60 moving inside the guide rail50 toward the vehicle front side shifts in the rail width direction soas to be gradually away from the side wall 58 located on the inner sidein the vehicle width direction. Thus, in the guide rail 50 of theembodiment, the guide roller 60 having entered the closing-side freerunning zone αc from the engaging zone β is quickly separated from theside wall 58 located on the inner side of the guide roller 60 in thevehicle width direction.

As shown in FIG. 11, in the step device 41 of the embodiment, a movingposition X1 of the guide roller 60 at the border between theclosing-side free running zone αc and the engaging zone β corresponds tothe retracted position P1 of the movable step 42. In the step device 41of the embodiment, when the sliding door 4 opens, the movable step 42reaches the deployed position P2 at the same time as shift of thesliding door 4 toward the outer side in the vehicle width direction iscompleted. In the step device 41 of the embodiment, as described above,the moving region Lo on the opening side from the moving position X2 atwhich the guide roller 60 is located when the movable step 42 reachesthe deployed position P2 is set as the opening-side free running zoneαo, so that the movable step 42 deployed under the door opening 3 doesnot put a load on the sliding door 4.

In particular, as shown in FIG. 11 and FIG. 14, in the vehicle 1 of theembodiment, when shift of the sliding door 4 in the vehicle widthdirection is completed, the guide roller 60 that moves integrally withthe sliding door 4 moves in the vehicle front-rear direction,substantially in a straight line. Based on this movement, a vehiclerear-side part of the guide rail 50 of the embodiment corresponding tothe moving region Lo on the opening side extends in the vehiclefront-rear direction, substantially in a straight line. Thus, in thestep device 41 of the embodiment, a parallel zone ε in which the sidewalls 57, 58 of the guide rail 50 extend parallel to the track ofmovement Qr of the guide roller 60 is formed, and the moving region Loon the opening side constitutes the opening-side free running zone αo.

Sub-Step

Next, the configuration of the sub-step 43 in the step device 41 of theembodiment will be described.

As shown in FIG. 6, FIG. 15, and FIG. 16A to FIG. 16C, in the stepdevice 41 of the embodiment, the sub-step 43 disposed under the dooropening 3 along with the movable step 42 includes a base part 71 that islocated above the movable step 42 and fixed to the side surface 2 a ofthe vehicle body 2 and a step part 72 that is coupled to the base part71 so as to be turnable in the up-down direction.

In the step device 41 of the embodiment, the base part 71 and the steppart 72 are coupled together through coupling shafts 73 that extend in alongitudinal direction of these parts. The base part 71 and the steppart 72 are formed respectively by laying, on base members 75, 76 thathave fitting portions 75 x, 76 x for the coupling shafts 73, resincovers 77, 78 that constitute decorative surfaces 71 s, 72 s of thesebase members 75, 76.

In the sub-step 43 of the embodiment, the base part 71 is fixed to theside surface 2 a of the vehicle body 2 in such a position that the steppart 72 that shifts in the up-down direction by turning around thecoupling shafts 73 comes into sliding contact with an upper surface 42a, i.e., the step surface S1, of the movable step 42 disposed under thesub-step 43.

In particular, the sub-step 43 of the embodiment has a structure inwhich a part of the resin cover 78 protrudes toward the side of a lowersurface 72 b at a leading end portion of the step part 72. In the stepdevice 41 of the embodiment, a projection 79 thus formed comes intosliding contact with the upper surface 42 a of the movable step 42.

Specifically, as shown in FIG. 4A to FIG. 6, the movable step 42 of theembodiment moves under the sub-step 43 toward the outer side in thevehicle width direction and is thereby disposed in the deployed positionP2 in which the movable step 42 protrudes from the sub-step 43 towardthe outer side in the vehicle width direction. Also when the movablestep 42 is in the deployed position P2, the sub-step 43 of theembodiment maintains the state where the step part 72 is in slidingcontact with the upper surface 42 a. The sub-step 43 has an overlappingregion η that covers an upper side of the movable step 42 in the statewhere the movable step 42 is disposed in the deployed position P2. Thus,in the sub-step 43 of the embodiment, the decorative surface 72 s of thestep part 72 forms a step surface S2 that is integral with the stepsurface S1 of the movable step 42.

In the step device 41 of the embodiment, the resin cover 78 constitutingthe step surface S2 of the step part 72 of the sub-step 43 hasdepressions and protrusions to prevent slipping, like the step surfaceS1 of the movable step 42. Thus, the step device 41 of the embodimentallows an occupant who has placed his or her foot on the sub-step 43 tosafely step onto the step surface S2.

Further, the sub-step 43 of the embodiment transfers a load applied tothe step surface S2 to the movable step 42 as the step part 72 turns. Inother words, in the step device 41 of the embodiment, a load applied tothe sub-step 43 is passed on to the movable step 42. Thus, the loadbearing capacity required of the sub-step 43 is reduced, which allowsfor reductions in the weight and manufacturing cost of the step device41 of the embodiment.

In the step device 41 of the embodiment, a plurality of ridges 80extending in the vehicle width direction is provided on the uppersurface 42 a of the movable step 42 with which the sub-step 43 comesinto sliding contact. Further, in the sub-step 43 of the embodiment, theprojection 79 provided at the leading end portion of the step part 72comes into sliding contact with the ridges 80. Thus, in the step device41 of the embodiment, the area of contact between the step part 72 ofthe sub-step 43 and the movable step 42 is reduced to thereby reduce thesliding resistance to the movable step 42 moving in the vehicle widthdirection.

Support Structure of Movable Step

Next, the structure of supporting the movable step 42 in the step device41 of the embodiment will be described.

As shown in FIG. 17A, FIG. 17B, FIG. 18, and FIG. 19, the step device 41of the embodiment includes, as the support arms 44 of the movable step42, two main arms 81 that are disposed apart from each other in thevehicle front-rear direction and a sub-arm 82 that is disposed betweenthe main arms 81. In the step device 41 of the embodiment, the sub-arm82 is formed by turnably coupling together a base end-side arm 83coupled to the vehicle body 2 and a leading end-side arm 84 coupled tothe movable step 42. The sub-arm 82 of the embodiment has a joint M3 atwhich the sub-arm 82 is bendable. The main arms 81 are not provided withthe joint M3. The step device 41 of the embodiment includes, as thesupport brackets 45, a front bracket 45 f that couples a front main arm81 f and the sub-arm 82 to the vehicle body 2 and a rear bracket 45 rthat couples a rear main arm 81 r to the vehicle body 2.

Specifically, as shown in FIG. 6 and FIG. 19 to FIG. 21, each supportbracket 45 of the embodiment includes a bracket main body 85 that isfixed to the lower surface 2 b of the vehicle body 2, and a holdingmember 86 that, together with the bracket main body 85, holds a base endpart 44 b of the support arm 44. In particular, the holding member 86 ofthe embodiment is disposed above the bracket main body 85, in such aposition that the base end part 44 b of the support arm 44 is heldbetween the holding member 86 and the bracket main body 85. In the stepdevice 41 of the embodiment, a shaft member 90 is inserted intoinsertion holes 87, 88 formed respectively in the bracket main body 85and the holding member 86 and an insertion hole 89 formed in the baseend part 44 b of the support arm 44. In the step device 41 of theembodiment, the shaft member 90 is clinched, and thus the supportbracket 45 forms the first pivot-joint point M1 of the support arm 44relative to the vehicle body 2.

As shown in FIG. 19, in the step device 41 of the embodiment,pluralities of fastening holes 85 x, 86 x are formed in the bracket mainbody 85 and the holding member 86, respectively. The fastening holes 85x, 86 x are used to fasten the bracket main body 85 and the holdingmember 86 of each support bracket 45 of the embodiment integrally andsimultaneously to the lower surface 2 b of the vehicle body 2.

FIG. 20 and FIG. 21 show the structure of supporting the front main arm81 f by a bracket main body 85 f and a holding member 86 f of a frontbracket 45 f. The structure of supporting the sub-arm 82 by the frontbracket 45 f, particularly the structure of holding the base end-sidearm 83 between the bracket main body 85 f and the holding member 86 f,is the same. Further, the structure of supporting the rear main arm 81 rby a bracket main body 85 r and a holding member 86 r of a rear bracket45 r is also the same as the support structure of the front bracket 45f. For the convenience of illustration, therefore, an enlarged view anda sectional view of the support structures for the sub-arm 82 and therear main arm 81 r are omitted.

As shown in FIG. 6 and FIG. 17A to FIG. 19, in the step device 41 of theembodiment, the leading end part 44 a of each support arm 44 is disposedon the lower surface 47 b of the movable base 47 constituting a part ofthe movable step 42. The leading end part 44 a of each support arm 44 isprovided with an insertion hole 91 similar to the insertion hole 89formed in the base end part 44 b. In the step device 41 of theembodiment, a shaft member 92 is inserted into the insertion hole 91 andthe insertion hole 49 of the movable base 47 constituting the couplingportion 46 on the side of the movable step 42. In the step device 41 ofthe embodiment, the shaft member 92 is clinched, and thus a secondpivot-joint point M2 of the support arm 44 relative to the movable step42 is formed.

As shown in FIG. 19, in the step device 41 of the embodiment, the baseend-side arm 83 constituting a part of the sub-arm 82 has an insertionhole 93, similar to the insertion hole 89 constituting the firstpivot-joint point M1 relative to the vehicle body 2, formed at an endportion on the opposite side from the side where the insertion hole 89is formed. Further, the leading end-side arm 84 has an insertion hole94, similar to the insertion hole 91 constituting the second pivot-jointpoint M2 relative to the movable step 42, formed at an end portion onthe opposite side from the side where the insertion hole 91 is formed.In the step device 41 of the embodiment, a shaft member 95 is insertedinto the insertion holes 93, 94. In the step device 41 of theembodiment, the shaft member 95 is clinched to form the joint M3 of thebendable sub-arm 82.

As shown in FIG. 17A and FIG. 17B, in the step device 41 of theembodiment, when the movable step 42 is in the retracted position P1,each support arm 44 is disposed such that the base end part 44 b thereofextends from the first pivot-joint point M1 relative to the vehicle body2 toward the vehicle front side. As the movable step 42 moves toward theouter side in the vehicle width direction in conjunction with opening ofthe sliding door 4, each support arm 44 turns in a counterclockwisedirection in FIG. 17A and FIG. 17B around the first pivot-joint point M1as a fulcrum, and as the movable step 42 moves toward the inner side inthe vehicle width direction, each support arm 44 turns in a clockwisedirection in FIG. 17A and FIG. 17B. Meanwhile, the base end-side arm 83and the leading end-side arm 84 of the sub-arm 82 turn relatively toeach other around the joint M3 so as to expand or contract thechevron-like bent shape. Thus, in the step device 41 of the embodiment,the second pivot-joint points M2 of the support arms 44 relative to themovable step 42 move in the vehicle front-rear direction while shiftingin the vehicle width direction, which allows the movable step 42 todeploy and retract smoothly in conjunction with opening and closing ofthe sliding door 4 while being stably supported.

As shown in FIG. 6, the step device 41 of the embodiment includes aplurality of pressure bearing members 100 that is provided under thesupport arms 44, each between the first pivot-joint point M1 relative tothe vehicle body 2 and the second pivot-joint point M2 relative to themovable step 42, so as to come into sliding contact with the support arm44 and bear the load thereof.

Specifically, as shown in FIG. 19 to FIG. 21, the step device 41 of theembodiment includes pressure bearing members 101 that are each fixed tothe bracket main body 85 of the support bracket 45 so as to come intosliding contact with the base end part 44 b of the support arm 44supported by the support bracket 45. In the step device 41 of theembodiment, the pressure bearing members 101 are provided so as tocorrespond to the respective support arms 44, namely the front main arm81 f and the sub-arm 82 supported by the front bracket 45 f and the rearmain arm 81 r supported by the rear bracket 45 r.

In the step device 41 of the embodiment, the pressure bearing members101 have substantially the same shape and pressure bearing structure.For the convenience of illustration, therefore, an enlarged view and asectional view of only the pressure bearing member 101 that is providedon the front bracket 45 f so as to correspond to the front main arm 81 fare shown in FIG. 20 and FIG. 21.

In particular, as shown in FIG. 22A and FIG. 22B, in the step device 41of the embodiment, each pressure bearing member 101 has a form of asubstantially arc-shaped flat plate. Each pressure bearing member 101has, on a back surface 101 b thereof, a pair of protruding fittingprojections 102. As the fitting projections 102 are fitted into mountingholes 103 (see FIG. 19) on the side of the bracket main body 85, thepressure bearing member 101 is fixed to the bracket main body 85 underthe support arm 44. Thus, as shown in FIG. 21, a front surface 101 a ofeach pressure bearing member 101 of the embodiment forms a slidingcontact surface 101 s that comes into sliding contact with the base endpart 44 b of the support arm 44 located above the pressure bearingmember 101.

More specifically, as shown in FIG. 20, each pressure bearing member 101is disposed on a radially outer side of the first pivot-joint point M1in such a state that the arc shape of the pressure bearing member 101extends in a circumferential direction around the first pivot-jointpoint M1. Thus, in the step device 41 of the embodiment, each pressurebearing member 101 has the sliding contact surface 101 s extending in adirection intersecting the corresponding support arm 44.

As shown in FIG. 19, FIG. 23, and FIG. 24, in the step device 41 of theembodiment, the movable step 42 is provided with a plurality of holdingmembers 110 that is each fixed to the movable base 47 so as to, togetherwith the lower surface 47 b of the movable base 47, hold the leading endpart 44 a of the support arm 44 at the coupling portion 46 for thesupport arm 44 provided in the movable base 47. The step device 41 ofthe embodiment includes a plurality of pressure bearing members 111 thatis each provided for the holding member 110 so as to come into slidingcontact with the leading end part 44 a of the support arm 44 held by theholding member 110.

In particular, as shown in FIG. 17A, FIG. 17B, and FIG. 18, the movablestep 42 of the embodiment is provided with a pair of front and rearholding members 110 that, together with the lower surface 47 b of themovable base 47, hold the pair of front and rear main arms 81 thatsupport the movable step 42 toward an upper side in a vehicle heightdirection (the left side in FIG. 18). The step device 41 of theembodiment includes a pair of pressure bearing members 111 provided onefor each holding member 110.

In the step device 41 of the embodiment, the holding members 110 havethe same shape and holding structure. For the convenience ofillustration, therefore, an enlarged view and a sectional view of onlythe holding member 110 that corresponds to the rear main arm 81 r areshown in FIG. 23 and FIG. 24.

Specifically, as shown in FIG. 19, FIG. 23, and FIG. 24, the holdingmember 110 of the embodiment has a form of a curved plate with asubstantially J-shaped cross-section, and includes a fixed part 112 thatis fixed to the movable base 47 and a holding part 113 that extendssubstantially parallel to the fixed part 112. The holding member 110 hasan insertion hole 114 extending through the holding part 113. In thestep device 41 of the embodiment, the shaft member 92 constituting thesecond pivot-joint point M2 of the support arm 44 relative to themovable step 42 is inserted into the insertion hole 91 provided in theleading end part 44 a of the support arm 44 and the insertion hole 49provided in the movable base 47 via the insertion hole 114. Thus, eachholding member 110 of the embodiment holds the leading end part 44 a ofthe support arm 44 between the holding part 113 and the lower surface 47b of the movable base 47 at the coupling portion 46 of the movable base47.

In the step device 41 of the embodiment, the holding member 110 is fixedto the movable step 42 as the fixed part 112 is welded to the uppersurface 47 a of the movable base 47. The holding part 113 of the holdingmember 110 is disposed on the side of the lower surface 47 b of themovable base 47 so as to surround a peripheral edge portion of themovable base 47. Thus, in the step device 41 of the embodiment, theforce with which the support arms 44 support the movable step 42,particularly the force with which the main arms 81 provided with theholding members 110 are supported is enhanced for the second pivot-jointpoint M2 relative to the movable step 42.

As shown in FIG. 25A and FIG. 25B, each pressure bearing member 111 ofthe embodiment has a form of a substantially rectangular flat plate witha bent portion 111 x at one end. The pressure bearing member 111 has, ona back surface 111 b thereof, a protruding fitting projection 115. Asthe fitting projection 115 is fitted into a mounting hole 116 providedin the holding part 113 of the holding member 110 (see FIG. 19), thepressure bearing member 111 is fixed to the holding member 110 under thesupport arm 44. Thus, as shown in FIG. 24, the front surface 111 a ofthe pressure bearing member 111 of the embodiment forms a slidingcontact surface 111 s that comes into sliding contact with the leadingend part 44 a of the support arm 44 located on the upper side of thepressure bearing member 111.

More specifically, as shown in FIG. 19 and FIG. 23, each main arm 81 ofthe embodiment has a substantially fan-shaped flat plate part 117 at apart with which the pressure bearing member 111 comes into slidingcontact. Thus, in the step device 41 of the embodiment, the area ofcontact between each main arm 81 and the pressure bearing member 111 isincreased to thereby enhance the force with which the main arm 81supports the movable step 42.

In the step device 41 of the embodiment, the pressure bearing members100, namely, the pressure bearing members 101 on the side of the firstpivot-joint points M1 provided on the support brackets 45 and thepressure bearing members 111 on the side of the second pivot-jointpoints M2 provided on the holding members 110, are each made of a resinhaving a shock absorbing property and a self-lubricating property.Examples of a resin material having these properties include polyacetal(POM). Thus, in the step device 41 of the embodiment, the support arms44 can turn smoothly and, at the same time, sliding noise thereof isreduced.

As shown in FIG. 26A, FIG. 26B, and FIG. 27, in the step device 41 ofthe embodiment, the lower surface 42 b of the movable step 42 isprovided with a plurality of ridges 118 that extends in directionsintersecting the support arms 44 located under the movable step 42 andcomes into sliding contact with the support arms 44.

As shown in FIG. 7, the movable step 42 of the embodiment includes threeridges 118 corresponding to the front main arm 81 f, the sub-arm 82, andthe rear main arm 81 r. The ridges 118 extend in a longitudinaldirection of the movable step 42 that extends in the vehicle front-reardirection.

As shown in FIG. 26A, FIG. 26B, and FIG. 27, in the movable step 42 ofthe embodiment, the ridges 118 are provided on the lower surface 48 b ofthe resin cover 48. The movable base 47 has elongated holes 119 atpositions under the respective ridges 118. In the movable step 42 of theembodiment, the ridges 118 inserted into the respective holes 119protrude toward the lower surface 47 b of the movable base 47constituting the lower surface 42 b of the movable step 42.

In the movable step 42 of the embodiment, the ridges 118 come intosliding contact with the support arms 44 located under the ridges 118,so that the support arms 44 can stably support the load of the movablestep 42. In the step device 41 of the embodiment, the ridges 118 extendin directions intersecting the support arms 44, which reduces the areaof contact between each ridge 118 and the corresponding support arm 44.Thus, in the movable step 42 of the embodiment, the support arms 44 canturn smoothly and, at the same time, sliding noise thereof is reduced.

As shown in FIG. 17A and FIG. 17B, the step device 41 of the embodimentincludes stoppers 120 that restrict the movable range of the movablestep 42 by coming into contact with the support arms 44. In particular,the step device 41 of the embodiment includes, as the stoppers 120, afirst stopper 121 provided on the front bracket 45 f and a secondstopper 122 provided on the rear bracket 45 r. The first stopper 121restricts turning of the front main arm 81 f by coming into contact withthe front main arm 81 f when the movable step 42 moves toward the innerside in the vehicle width direction and reaches the retracted positionP1. The second stopper 122 restricts turning of the rear main arm 81 rby coming into contact with the rear main arm 81 r when the movable step42 moves toward the outer side in the vehicle width direction andreaches the deployed position P2. By thus restricting the movable rangeof the movable step 42, the step device 41 of the embodiment preventsthe chevron-like bent shape of the sub-arm 82 from becoming inverted.

Protective Cover

Next, the configuration of a protective cover provided in the stepdevice 41 of the embodiment will be described.

As shown in FIG. 6 and FIG. 27 to FIG. 30, the step device 41 of theembodiment includes a cover member 130 that is fixed to the lowersurface 2 b of the vehicle body 2 so as to cover lower sides of thesupport arms 44.

Specifically, the cover member 130 of the embodiment includes a bottomwall 131 that is disposed under the support arms 44 and a peripheralwall 132 that is erected at edges of the bottom wall 131 so as to extendupward toward the lower surface 2 b of the vehicle body 2. In the covermember 130 of the embodiment, the bottom wall 131 is formed to be largeenough to cover the lower sides of support arms 44 when the movable step42 is in the retracted position P1. The peripheral wall 132 is erectedat the edges of the bottom wall 131 so as to extend on the vehicle frontside, the inner side in the vehicle width direction, and the vehiclerear side of the cover member 130. Thus, the cover member 130 of theembodiment forms a housing space 133 opening toward the outer side inthe vehicle width direction, at a lower level than the lower surface 2 bof the vehicle body 2.

In particular, the cover member 130 of the embodiment is fastened alongwith the support brackets 45 of the support arms 44 to the lower surface2 b of the vehicle body 2 by means of fastening portions 134 that areintegrally formed in the peripheral wall 132. In the vehicle 1 of theembodiment, the cover member 130 forms the housing space 133 togetherwith the lower surface 2 b of the vehicle body 2 and the lower surface43 b of the sub-step 43, both located above the cover member 130. Thus,in the step device 41 of the embodiment, when the movable step 42 is inthe retracted position P1, the substantially entire movable step 42 ishoused along with the support arms 44 inside the housing space 133formed by the cover member 130.

More specifically, as shown in FIG. 27 to FIG. 30, the cover member 130of the embodiment includes a seal member 135 that is interposed betweenthe peripheral wall 132 and the vehicle body 2. In particular, the sealmember 135 of the embodiment has a string-like outer shape with asubstantially quadrangular cross-section. In the cover member 130 of theembodiment, the seal member 135 having such an outer shape is dividedinto parts and fixed to a leading end of the peripheral wall 132 erectedat the edges of the bottom wall 131.

In particular, as shown in FIG. 31 and FIG. 32, the cover member 130 ofthe embodiment has a plurality of notches 132 x that is provided in aperipheral wall part 132 i on the inner side in the vehicle widthdirection to avoid interference with the support brackets 45 of thesupport arms 44. In the cover member 130 of the embodiment, the sealmember 135 is provided also at the notches 132 x along the edge of thebottom wall 131 continuously from the peripheral wall part 132 i byhaving its string-like shape bent into a substantially square-U-shape.Thus, as shown in FIG. 27 and FIG. 30, in the cover member 130 of theembodiment, the seal member 135 is interposed also between the supportbracket 45 and the peripheral wall part 132 i.

As shown in FIG. 33, in the cover member 130 of the embodiment, the sealmember 135 is provided also at a corner between the peripheral wall part132 i on the inner side in the vehicle width direction and a peripheralwall part 132 f on the vehicle front side along the edge of the bottomwall 131 by having its string-like shape bent into a substantiallyL-shape. Thus, in the step device 41 of the embodiment, foreign objects,such as dust or mud water, are kept from entering the housing space 133formed by the cover member 130 through a gap between the peripheral wall132 of the cover member 130 and the lower surface 2 b of the vehiclebody 2.

As shown in FIG. 33 and FIG. 34, in the cover member 130 of theembodiment, a sloping surface 140 that slopes downward while extendingfrom the vehicle front side toward the vehicle rear side is provided atthe vehicle front-side peripheral wall part 132 f that is provided at afront end portion 130 f of the cover member 130. The long dasheddouble-short dashed line in FIG. 34 indicates the shape of the slopingsurface 140 at a part where the fastening portion 134 is not provided.Based on the shape of the sloping surface 140, the cover member 130 ofthe embodiment mitigates the impact of foreign objects that, while thevehicle is running, collide from the vehicle front side with theperipheral wall part 132 f provided at the front end portion 130 f, suchas small stones kicked up by a tire of the vehicle 1.

In the vehicle 1 of the embodiment, when the movable step 42 is in theretracted position P1, an opening 141 of the housing space 133 facingthe outer side in the vehicle width direction is closed with adecorative member 142 (see FIG. 6) provided at a lower end of thesliding door 4. Thus, the step device 41 of the embodiment preventsforeign objects from entering the housing space 133 through the openpart on the outer side in the vehicle width direction while the vehicle1 is running.

As shown in FIG. 28, the cover member 130 of the embodiment includes afitting member 144 that is fitted into a window 143 provided in theperipheral wall part 132 i on the inner side in the vehicle widthdirection and thereby integrated with the peripheral wall part 132 i ina state of closing the window 143. In the step device 41 of theembodiment, the fitting member 144 can be removed to maintain thesupport arms 44 disposed inside the housing space 133 through the window143.

Further, as shown in FIG. 6, FIG. 21, FIG. 27, and FIG. 30, the stepdevice 41 of the embodiment includes a seal member 145 that isinterposed between the bracket main body 85 and the holding member 86composing the support bracket 45 of each support arm 44. In particular,in the step device 41 of the embodiment, the seal member 145 has astring-like outer shape with a substantially quadrangular cross-section,like the seal member 135 interposed between the peripheral wall 132 ofthe cover member 130 and the lower surface 2 b of the vehicle body 2. Inthe step device 41 of the embodiment, the seal member 145 is disposed soas to surround the base end part 44 b of each support arm 44 heldbetween the bracket main body 85 and the holding member 86 such thatforeign objects are kept from entering the first pivot-joint point M1 ofthe support arm 44 relative to the support bracket 45.

As shown in FIG. 6, in the step device 41 of the embodiment, the covermember 130 is disposed at a higher level than a lower end 150 b of arocker flange 150 that is provided on the lower surface 2 b of thevehicle body 2. Thus, in the step device 41 of the embodiment, the covermember 130 does not get in the way of lifting up the vehicle 1 using therocker flange 150.

Coupling Structure of Guide Roller Unit

Next, the structure of coupling the guide roller unit 52 to the guiderail 50 in the step device 41 of the embodiment will be described.

As shown in FIG. 10, FIG. 35A, and FIG. 35B, the guide roller unit 52 asa coupling member in the step device 41 of the embodiment has astructure in which the fixed member 61 that is fixed to the sliding door4 and the arm member 62 that supports, at a leading end thereof, theguide roller 60 as the engaging part engaged with the guide rail 50 areturnably coupled together through a shaft member 160.

In particular, in the guide roller unit 52 of the embodiment, the fixedmember 61 includes a main body 161 that is fixed to the sliding door 4in a state of extending in the up-down direction, and a pair of oppositewalls 163 that are provided at a lower end portion of the main body 161and face each other. The arm member 62 includes a main body 164 that hasa substantially flat-plate-like outer shape, and a pair of oppositewalls 166 that are provided on a base end side of the main body 164 andface each other. In the guide roller unit 52 of the embodiment, theopposite walls 163 on the side of the fixed member 61 and the oppositewalls 166 on the side of the arm member 62 have insertion holes 167,168, respectively, formed at such positions as to face each other. Inthe guide roller unit 52 of the embodiment, the fixed member 61 and thearm member 62 are turnably coupled together as the shaft member 160 isinserted into the insertion holes 167, 168.

The guide roller unit 52 of the embodiment is provided with a helicaltorsion spring 170 that is interposed between the fixed member 61 andthe arm member 62, with the shaft member 160 inserted in the helicaltorsion spring 170. In the guide roller unit 52 of the embodiment, basedon an elastic force of the helical torsion spring 170 as an urgingmember, an urging force in the direction of lifting upward the guideroller 60 supported at the leading end of the arm member 62 is appliedto the arm member 62 in a state where the fixed member 61 is fixed tothe sliding door 4.

As shown in FIG. 35A, when the guide roller unit 52 of the embodiment isin a state of being coupled to the guide rail 50 provided on the movablestep 42, the guide roller 60 is supported inside the guide rail 50 witha leading end side of the arm member 62 lifted upward based on theurging force of the helical torsion spring 170.

As shown in FIG. 35B, when the guide roller unit 52 of the embodiment isin an uncoupled state where the guide roller 60 is separated from theguide rail 50, the arm member 62 turns further such that the leading endside thereof supporting the guide roller 60 comes closer to the mainbody 161 of the fixed member 61 based on the urging force of the helicaltorsion spring 170. Thus, in the step device 41 of the embodiment, theguide roller unit 52 can be compactly folded, so that work efficiency inthe uncoupled state is increased and, at the same time, the guide rollerunit 52 does not get in the way of an occupant using the sliding door 4.

As shown in FIG. 10, FIG. 35A, and FIG. 35B, the guide roller unit 52 ofthe embodiment has a stopper 171 that is integrally provided on theopposite wall 166 a of the arm member 62. When the guide roller unit 52is in the uncoupled state, the stopper 171 comes into contact with themain body 161 of the fixed member 61 as the arm member 62 turns based onthe urging force of the helical torsion spring 170. Thus, in the guideroller unit 52 of the embodiment, the amount of turning of the armmember 62 is restricted such that the arm member 62 urged by the helicaltorsion spring 170 and the guide roller 60 supported by the arm member62 do not interfere with the sliding door 4.

As shown in FIG. 7, FIG. 8, FIG. 18, and FIG. 36, the guide rail 50 ofthe embodiment has notches 180 formed by cutting out portions of thefall prevention flange 59 provided at the lower end of the side wall 58.In the step device 41 of the embodiment, the notches 180 can be used toinsert and remove the guide roller 60 of the guide roller unit 52supported by the sliding door 4 into and from the guide rail 50 providedon the lower surface 42 b of the movable step 42.

As shown in FIG. 36, at longitudinal positions at which the notches 180are provided, the guide rail 50 of the embodiment allows the guideroller 60 to move in the up-down direction beyond the fall preventionflange 59 provided at the lower end of the side wall 58. Further, in theguide roller unit 52 of the embodiment, the arm member 62 can be presseddownward so as to turn against the urging force of the helical torsionspring 170. In the guide roller unit 52 of the embodiment, meanwhile, astopper 172 (see FIG. 10) integrally provided on the opposite wall 166 aof the arm member 62 comes into contact with the main body 161 of thefixed member 61 and thereby restricts the amount of turning of the armmember 62 in the downward pressing direction. In the guide roller unit52 of the embodiment, when this downward pressing force is removed, thearm member 62 can be turned again based on the urging force of thehelical torsion spring 170.

Thus, in the step device 41 of the embodiment, the notches 180 providedin the guide rail 50 can be used to insert the guide roller 60 providedat the leading end of the arm member 62 into the guide rail 50 frombelow by turning the arm member 62 based on the urging force of thehelical torsion spring 170. Moreover, the guide roller 60 supportedinside the guide rail 50 can be separated downward from the guide rail50 by turning the arm member 62 against the urging force of the helicaltorsion spring 170. Thus, in the step device 41 of the embodiment, thesliding door 4 supporting the guide roller unit 52 and the movable step42 provided with the guide rail 50 can be easily coupled to anduncoupled from each other.

Specifically, as shown in FIG. 7, FIG. 8, FIG. 18, and FIG. 37, theguide rail 50 of the embodiment includes a notch 181 provided at alongitudinal end portion 50 r on the vehicle rear side where the guideroller 60 is located when the sliding door 4 is fully opened. Thus, inthe step device 41 of the embodiment, the sliding door 4 and the movablestep 42 can be coupled to and uncoupled from each other in a state wherea sufficient working space is easy to secure owing to the movable step42 being disposed in the deployed position P2 on the outer side in thevehicle width direction and the sliding door 4 being fully opened.

As shown in FIG. 7, FIG. 8, FIG. 18, and FIG. 38, the guide rail 50 ofthe embodiment has a notch 182 provided at a longitudinal position onthe vehicle front side relative to the notch 181. In particular, thenotch 182 is formed at a corner 70 c provided farthest on the vehiclerear side in the curved portion 70 that is provided at the longitudinalend portion 50 f on the vehicle front side. Thus, in the step device 41of the embodiment, also when the sliding door 4 is located near thefully closed position Pc, the sliding door 4 and the movable step 42 canbe coupled to and uncoupled from each other in a state where a workingspace is easy to secure owing to the sliding door 4 having shiftedtoward the outer side in the vehicle width direction by opening and themovable step 42 having moved toward the outer side in the vehicle widthdirection.

The step device 41 of the embodiment includes a retaining member 190that retains the movable step 42 in the retracted position P1 on theinner side in the vehicle width direction when the guide roller 60 isseparated from the guide rail 50, i.e., the sliding door 4 and themovable step 42 are uncoupled from each other.

As shown in FIG. 28, FIG. 29A, FIG. 29B, and FIG. 33, in the step device41 of the embodiment, the retaining member 190 is provided on the covermember 130 forming the housing space 133 when the movable step 42 is inthe retracted position P1. In particular, the retaining member 190 ofthe embodiment is provided on the bottom wall 131, near the front endportion 130 f of the cover member 130. The retaining member 190 has ahook-shaped engaging projection 191. The retaining member 190 of theembodiment retains the movable step 42 in the retracted position P1 byhaving the engaging projection 191 engaged with the movable step 42.

Specifically, as shown in FIG. 39A and FIG. 39B, the retaining member190 of the embodiment is turnably coupled to the bottom wall 131 of thecover member 130. In the step device 41 of the embodiment, turning thecover member 130 around a support shaft 190 x can switch between a usedstate where the engaging projection 191 does not engage with the movablestep 42 and a retained state where the engaging projection 191 engageswith the movable step 42 disposed in the retracted position P1.

In particular, as shown in FIG. 39A, in the used state where the movablestep 42 is moved in the vehicle width direction in conjunction with thesliding door 4, the retaining member 190 of the embodiment is kept in astate where the engaging projection 191 faces the outer side in thevehicle width direction. Thus, in the step device 41 of the embodiment,the engaging projection 191 of the retaining member 190 does notinterfere with the movable step 42 that moves in the vehicle widthdirection.

As shown in FIG. 39B, in the step device 41 of the embodiment, when themovable step 42 uncoupled from the sliding door 4 is to be retained inthe retracted position P1, the retaining member 190 is turned in acounterclockwise direction in FIG. 39A and FIG. 39B, so that theengaging projection 191 faces the vehicle rear side where the movablestep 42 is disposed. In the step device 41 of the embodiment, as theretaining member 190 thus turns, the engaging projection 191 is insertedinto an engaging recess 192 provided at a front end portion 42 f of themovable step 42.

In the step device 41 of the embodiment, the engaging projection 191 ofthe retaining member 190 inserted into the engaging recess 192 of themovable step 42 is disposed inside the guide rail 50 at the longitudinalend portion 50 f on the vehicle front side. Thus, the step device 41 ofthe embodiment can retain the movable step 42 in the retracted positionP1 as the retaining member 190 engages with the movable step 42.

Next, effects of the embodiment will be described. The step device 41includes the movable step 42 that is supported under the door opening 3,and the guide roller unit 52 as the coupling member that, in the stateof being supported by the sliding door 4, engages with the movable step42 to move the movable step 42 in the vehicle width direction inconjunction with opening and closing of the sliding door 4. The stepdevice 41 includes the support arms 44 that each have the firstpivot-joint point M1 relative to the vehicle body 2 and the secondpivot-joint point M2 relative to the movable step 42, and support themovable step 42 toward the upper side. The step device 41 furtherincludes the pressure bearing members 100 that are each provided at aposition between the first pivot-joint point M1 relative to the vehiclebody 2 and the second pivot-joint point M2 relative to the movable step42 and bear the load of the support arm 44 by coming into slidingcontact with the support arm 44.

In this configuration, each pressure bearing member 100 supports theload of the support arm 44, so that the load of the movable step 42supported by the support arm 44 is less likely to concentrate at thefirst pivot-joint point M1 of the support arm 44 relative to the vehiclebody 2 and the second pivot-joint point M2 of the support arm 44relative to the movable step 42. Thus, higher supporting rigidity can besecured.

The step device 41 has the support brackets 45 that are each fixed tothe vehicle body 2 to form the first pivot-joint point M1 of the supportarm 44 relative to the vehicle body 2, and the pressure bearing members101 that are each provided on the support bracket 45.

In this configuration, each pressure bearing member 101 provided on thesupport bracket 45 supports the load of the support arm 44, so that theload of the movable step 42 supported by the support arm 44 is lesslikely to concentrate at the first pivot-joint point M1 of the supportarm 44 relative to the vehicle body 2. Thus, higher supporting rigiditycan be secured.

The step device 41 includes the holding members 110 that are each fixedto the movable step 42 so as to hold, together with the movable step 42,the support arm 44 at the second pivot-joint point M2 thereof relativeto the movable step 42, and the pressure bearing members 111 that areeach provided on the holding member 110.

In this configuration, each holding member 110 holds, together with themovable step 42, the support arm 44, which increases the supportingrigidity of the support arm 44 at the second pivot-joint point M2thereof relative to the movable step 42. Further, each pressure bearingmember 111 provided on the holding member 110 supports the load of thesupport arm 44, so that the load of the movable step 42 is less likelyto concentrate at the second pivot-joint point M2. Thus, highersupporting rigidity can be secured.

The pressure bearing members 101 provided on the support brackets 45have an outer form of a substantially arc-shaped flat plate. Thepressure bearing members 101 are each disposed on the radially outerside of the first pivot-joint point M1 in such a state that the arcshape of the pressure bearing member 101 extends in the circumferentialdirection around the first pivot-joint point M1.

In this configuration, each pressure bearing member 101 forms thesliding contact surface 101 s extending in a direction intersecting thesupport arm 44. As a result, the pressure bearing member 101 can bestably brought into sliding contact with the support arm 44 that turnsaround the first pivot-joint point M1 as a fulcrum. Thus, highersupporting rigidity can be secured.

The pressure bearing members 100 are made of a resin having a shockabsorbing property and a self-lubricating property. This configurationmakes it possible to ensure smooth turning of the support arms 44 byabsorbing a shock load of the movable step 42 transmitted to the supportarms 44 and, at the same time, to reduce the sliding sound of thesupport arms 44.

The ridges 118 that each extend in a direction intersecting the supportarm 44 and come into sliding contact with the support arm 44 is providedon the lower surface 42 b of the movable step 42. In this configuration,each ridge 118 provided on the movable step 42 comes into slidingcontact with the support arm 44 located under the ridge 118, so that theload of the movable step 42 can be stably supported. Further, as theridge 118 extends in a direction intersecting the support arm 44, thearea of contact between the ridge 118 and the support arm 44 can bereduced. Thus, it is possible to ensure smooth turning of the supportarms 44 and, at the same time, to reduce the sliding sound of thesupport arms 44.

The movable step 42 includes the movable base 47 having the couplingportions 46 for the support arms 44, and the resin cover 48 that isfixed to the movable base 47 to be the step surface S1. The ridges 118are each provided on the lower surface 48 b of the resin cover 48 andprotrude toward the side of the lower surface 42 b of the movable step42 through the hole 119 provided in the movable base 47.

This simple configuration makes it possible to impart a shock absorbingproperty and a self-lubricating property to the ridges 118 whilesecuring the strength of the movable base 47. Thus, smoother turning ofthe support arms 44 can be ensured.

The step device 41 includes, as the support arms 44, the two main arms81 that are provided at positions apart from each other in the vehiclefront-rear direction, and the sub-arm 82 that has the joint M3 at whichthe sub-arm 82 is bendable and that is provided at a position apart fromeach main arm 81.

In this configuration, the bent shape of the sub-arm 82 having the jointM3 changes such that the turning sub-arm 82 does not interfere with eachturning main arm 81. Thus, the number of the support arms 44 can beincreased to enhance the supporting rigidity for the movable step 42,while smooth movement of the movable step 42 is ensured.

The sub-arm 82 is provided between the main arms 81. In thisconfiguration, the two main arms 81 can be disposed a greater distanceapart from each other in the vehicle front-rear direction. Thus, themovable step 42 can be more stably supported.

The step device 41 includes the stoppers 120 that restrict the movablerange of the movable step 42 by coming into contact with the supportarms 44. In this configuration, the movable step 42 supported by thesupport arms 44 can be appropriately moved in the vehicle widthdirection between the retracted position P1 and the deployed positionP2. Thus, the quality of the movable step 42 can be enhanced. Moreover,the sub-arm 82 can be prevented from turning excessively and invertingits bent shape. Thus, high reliability can be ensured.

The above embodiment can be implemented with changes made thereto asfollows. The embodiment and the following modified examples can beimplemented in combination within such a range that no technicalinconsistency arises.

In the above embodiment, the present disclosure is implemented as thestep device 41 that operates in conjunction with the rearward openingsliding door 4 that opens toward the vehicle rear side. However, thedisclosure may instead be applied to a frontward opening sliding door 4that opens toward the vehicle front side.

In the above embodiment, the sliding door 4 is opened and closed bybeing driven by the power sliding door device 31. However, thedisclosure may instead be applied to a sliding door 4 that does not havesuch a power sliding door device 31.

In the above embodiment, the power sliding door device 31 functions asthe catching detection device 32 that detects whether any object iscaught in the sliding door 4 based on changes in the force required toopen and close the sliding door 4. As one example of this detection, thepower sliding door device 31 determines that an object is caught in thesliding door 4 when the amount of current to the motor 31 m increasesbeyond a predetermined threshold value while the sliding door 4 isdriven to open or close. However, the present disclosure is not limitedto this example, and detection of whether any object is caught in thesliding door 4 may instead be based on changes in rotation of the motor31 m. Further, the disclosure may be applied to a sliding door 4provided with a catching detection device 32 independent of the powersliding door device 31, as long as the catching detection device 32executes detection of whether any object is caught in the sliding door 4based on changes in the force required to open or close the sliding door4. In addition, the disclosure may be applied to a sliding door 4 thatis not provided with such a catching detection device 32.

In the above embodiment, the movable step 42 moves in the vehicle widthdirection while maintaining the substantially horizontal posture.However, the posture need not be necessarily horizontal and may insteadbe, for example, inclined downward toward the outer side in the vehiclewidth direction.

In the above embodiment, in the guide rail 50, the peripheral wall 55 ofthe movable base 47 constituting the lower surface 42 b of the movablestep 42 forms the side wall 57 on the outer side in the vehicle widthdirection, and the rail members 53, 54 facing the peripheral wall 55 inthe vehicle width direction form the side wall 58 on the inner side inthe vehicle width direction. However, the present disclosure is notlimited to this example, and two independent wall members formed asparts separate from the movable step 42 may be fixed to the lowersurface 42 b of the movable step 42 to form the side walls 57, 58 of theguide rail 50. Alternatively, for example, a rail member with asubstantially square-U-shaped cross-section opening downward may befixed to the lower surface 42 b of the movable step 42 to form the guiderail 50. In addition, the guide rail 50 may be integrally formed in themovable step 42.

In the above embodiment, the closing-side free running zone αcconstitutes the non-sliding-contact zone γ in which the guide roller 60moving inside the guide rail 50 in the vehicle front-rear directionmoves in the vehicle width direction while shifting in the rail widthdirection of the guide rail 50 without coming into sliding contact withthe side walls 57, 58. The opening-side free running zone αo constitutesthe parallel zone ε in which the side walls 57, 58 of the guide rail 50extend parallel to the track of movement Qr of the guide roller 60.However, the present disclosure is not limited to this example, and theclosing-side free running zone αc may constitute the parallel zone ε.The opening-side free running zone αo may constitute thenon-sliding-contact zone γ.

In the above embodiment, in the non-sliding-contact zone γ, the gradientof change θ1 of the side wall 57 on the outer side in the vehicle widthdirection is set to be smaller than the gradient of change θr set forthe track of movement Qr of the guide roller 60, and the gradient ofchange θ2 of the side wall 58 on the inner side in the vehicle widthdirection is set to be larger than the gradient of change θr. However,the present disclosure is not limited to this example, and for example,simply a larger rail width may be set, as long as the guide roller 60moving inside the guide rail 50 in the vehicle front-rear direction canmove in the vehicle width direction while shifting in the rail widthdirection of the guide rail 50 without coming into sliding contact withthe side walls 57, 58.

In the above embodiment, during opening of the sliding door 4, themovable step 42 reaches the deployed position P2 at the same time asshift of the sliding door 4 toward the outer side in the vehicle widthdirection is completed. However, the present disclosure is not limitedto this example, and as shown in FIG. 40, during opening of the slidingdoor 4, the movable step 42 may reach the deployed position P2 beforeshift of the sliding door 4 toward the outer side in the vehicle widthdirection is completed.

An occupant of the vehicle 1 may start to get in or out of the vehicle 1when shift of the sliding door 4 toward the outer side in the vehiclewidth direction is completed, even if the sliding door 4 is stillopening. In the above configuration, the movable step 42 has alreadyreached the deployed position P2 by that time. This can reduce thelikelihood that an occupant may place his or her foot on the movablestep 42 that is moving outward in the vehicle width direction.

Further, the moving position X3 at which the guide roller 60 is locatedwhen shift of the sliding door 4 toward the outer side in the vehiclewidth direction is completed is already in the opening-side movingregion Lo, i.e., the opening-side free running zone ow set for the guiderail. Thus, even when an occupant of the vehicle 1 places his or herfoot on the movable step 42 before shift of the sliding door 4 towardthe outer side in the vehicle width direction is completed, the movablestep 42 is less likely to put a load on the sliding door 4.

In the above embodiment, the sub-step 43 is formed by turnably couplingthe step part 72 forming the step surface S2 to the base part 71 that isfixed to the vehicle body 2. However, the present disclosure is notlimited to this example, and the base part 71 and the step part 72 maybe fixed to each other in a substantially L-shape.

In the above embodiment, the base part 71 and the step part 72 of thesub-step 43 are formed by laying the resin covers 77, 78 on the basemembers 75, 76, but instead both or one of the base part 71 and the steppart 72 may be composed of a single part. Alternatively, the base part71 and the step part 72 may be integrally formed.

In the above embodiment, in the sub-step 43, the projection 79 providedon the resin cover 78 so as to protrude toward the side of the lowersurface 72 b comes into sliding contact with the upper surface 42 a ofthe movable step 42 at the leading end portion of the step part 72.However, the present disclosure is not limited to this example, and theportion at which the step part 72 of the sub-step 43 comes into slidingcontact with the upper surface 42 a of the movable step 42 need not benecessarily the leading end portion and may instead be a portion on thebase end side.

The step part 72 of the sub-step 43 and the upper surface 42 a of themovable step 42 need not necessarily directly come into sliding contactwith each other, and may instead, for example, come into sliding contactwith each other through an attached part having elasticity, such as abrush or a lip seal. Alternatively, a gap may be left between the lowersurface 72 b of the step part 72 on the side of the sub-step 43 and theupper surface 42 a of the movable step 42, without these surfaces cominginto sliding contact with each other.

As in a step device 41B shown in FIG. 41, movement of a movable step 42Btoward the outer side in the vehicle width direction may be restrictedas a first engaging part 201 provided on the movable step 42B and asecond engaging part 202 provided on a sub-step 43B engage with eachother when the movable step 42B moves to the deployed position P2.

For example, in the step device 41B, an engaging projection 205protruding toward the upper side of the movable step 42B is provided ata base end portion 203 of the movable step 42B. An engaging projection208 protruding toward the lower side of a step part 72B of the sub-step43B is provided at a leading end portion 206 of the step part 72B. Inthe step device 41B, the engaging projection 205 engages with theengaging projection 208 on the side of the sub-step 43B when the movablestep 42B moves toward the outer side in the vehicle width direction andreaches the deployed position P2. In the step device 41B, the engagingprojections 205, 208 serve as the first engaging part 201 and the secondengaging part 202 to restrict movement of the movable step 42B towardthe outer side in the vehicle width direction.

This configuration can maintain a constant positional relationshipbetween the movable step 42B and the sub-step 43B when the movable step42B is in the deployed position P2. This makes it possible to furtherenhance the unity of the step surface S1 of the movable step 42 and thestep surface S2 of the sub-step 43 by, for example, connecting the stepsurfaces S1, S2 of the movable step 42 and the sub-step 43 to each otherso as to obscure the border between the decorative shapes thereof.

The shapes of the first engaging part 201 and the second engaging part202 may be arbitrarily changed. For example, one of the first engagingpart 201 and the second engaging part 202 may have a recessed shape.Further, the position at which the first engaging part 201 is formedneed not necessarily be the base end portion 203 of the movable step42B. The position at which the second engaging part 202 is formed neednot necessarily be the leading end portion 206 of the step part 72B,either.

In the above embodiment, the pressure bearing members 100 are made of aresin having a shock absorbing property and a self-lubricating property.However, the material of the pressure bearing members 100 may bearbitrarily changed. As long as the pressure bearing members 100 cancome into sliding contact with the support arms 44 and bear the loadthereof, the pressure bearing member 101 provided on the support bracket45 and the pressure bearing member 111 on the side of the movable step42 provided on the holding member 110 may be made of differentmaterials. For example, one of the pressure bearing members 101, 111 maybe made of resin and the other may be made of metal. The possibility offorming both the pressure bearing members 101, 111 using other materialsthan resin is not eliminated.

The shape of the pressure bearing members 100 may be arbitrarilychanged. For example, the pressure bearing member 111 on the side of themovable step 42 may have a form of a substantially arc-shaped flatplate, like the pressure bearing member 101 on the side of the supportbracket 45. Further, at least one of the pressure bearing members 101,111 may form a sliding contact surface of other shape than an arc shapethat extends in a direction intersecting the support arm 44. Thepressure bearing member 101 on the side of the support bracket 45 mayhave a form of a substantially rectangular flat plate, like the pressurebearing member 111 on the side of the movable step 42.

The number and arrangement of the pressure bearing members 100 may alsobe arbitrarily changed. For example, only one of the pressure bearingmember 101 on the side of the support bracket 45 and the pressurebearing member 111 on the side of the movable step 42 may be provided.In the above embodiment, only the main arms 81 are each provided withthe holding member 110 and the pressure bearing member 111. However, thesub-arm 82 may also be provided with a similar holding member 110 andpressure bearing member 111. Further, only the sub-arm 82, or thesub-arm 82 and one of the main arms 81 may be provided with the holdingmember 110 and the pressure bearing member 111. In the above embodiment,all the support arms 44 are provided with the pressure bearing member101 on the side of the support bracket 45. However, the pressure bearingmember 101 on the side of the support bracket 45 may be selectivelyprovided; for example, only the main arms 81 may be each provided withthe pressure bearing member 101 on the support bracket 45.

In the above embodiment, the ridges 118 provided on the lower surface 48b of the resin cover 48 protrude toward the lower surface 42 b of themovable step 42 through the holes 119 provided in the movable base 47.However, the present disclosure is not limited to this example, and thestructure and material of the ridges 118 may be arbitrarily changed. Forexample, the ridges 118 may be made of metal. The ridges 118 may beprovided on the member forming the lower surface 42 b of the movablestep 42.

In the above embodiment, the step device 41 includes, as the supportarms 44, two main arms 81 and one sub-arm 82 provided between the mainarms 81. However, the present disclosure is not limited to this example,and the number and arrangement of the sub-arm 82 may be arbitrarilychanged. For example, two or more sub-arms 82 may be provided. A sub-arm82 may be provided on the vehicle front side or the vehicle rear side ofthe main arms 81. Alternatively, the sub-arm 82 may be omitted and themovable step 42 may be supported by two main arms 81.

A configuration may be adopted in which the support arms 44 that areturnably coupled to both the vehicle body 2 and the movable step 42 areused in combination with other support structure, for example, arail-and-slider.

In the above embodiment, the step device 41 includes, as the stoppers120, the first stopper 121 that restricts turning of the front main arm81 f by coming into contact with the front main arm 81 f when themovable step 42 reaches the retracted position P1, and the secondstopper 122 that restricts turning of the rear main arm 81 r by cominginto contact with the rear main arm 81 r when the movable step 42reaches the deployed position P2. However, the present disclosure is notlimited to this example, and the configuration and arrangement of thestoppers 120 may be arbitrarily changed as long as the stoppers 120restrict the movable range of the movable step 42 by coming into contactwith the support arms 44.

The material of the cover member 130 may be arbitrarily changed. Thematerial may be resin or metal. In the above embodiment, the covermember 130 includes the bottom wall 131 that is disposed under thesupport arms 44 and the peripheral wall 132 that is provided at theedges of the bottom wall 131. However, the shape of the cover member 130may be arbitrarily changed. For example, the cover member 130 may have adome shape or the like in which there is no distinction between thebottom wall 131 and the peripheral wall 132. The seal member 135interposed between the vehicle body 2 and the peripheral wall 132 may beomitted. The possibility of leaving a gap between the cover member 130and the lower surface 2 b of the vehicle body 2 is not eliminated.

In the above embodiment, the cover member 130 forms the housing space133 together with the lower surface 2 b of the vehicle body 2 and thelower surface 43 b of the sub-step 43. Alternatively, the cover member130 may form the housing space 133 together with only the lower surface2 b of the vehicle body 2.

In the state where the movable step 42 is in the retracted position P1,at least part of the step surface S1 may be exposed toward the upperside. The lower surface 42 b of the movable step 42 may be partiallyexposed toward the lower side of the cover member 130.

In the above embodiment, the helical torsion spring 170 is used as theurging member that applies an urging force in the direction of liftingthe guide roller 60 to the arm member 62. However, other elastic member,such as an extension spring or a compression spring, may be used as theurging member.

In the above embodiment, the guide rail 50 has, as the notches 180, thenotch 181 provided at the longitudinal end portion 50 r on the vehiclerear side and the notch 182 formed at the corner 70 c farthest on thevehicle rear side in the curved portion 70 provided at the longitudinalend portion 50 f on the vehicle front side. However, the presentdisclosure is not limited to this example, and the number andarrangement of the notches 180 may be arbitrarily changed. For example,there may be only one notch 180 and that notch 180 may be the notch 181at the longitudinal end portion 50 r on the vehicle rear side.Alternatively, three or more notches 180 may be provided apart from oneanother in the longitudinal direction of the guide rail 50.

In the above embodiment, the fall prevention flange 59 is provided atthe lower end portion of the side wall 58 on the inner side in thevehicle width direction. However, the fall prevention flange 59 mayinstead be provided at the lower end portion of the side wall 57 on theouter side in the vehicle width direction.

In the above embodiment, the retaining member 190 has the hook-shapedengaging projection 191 and is coupled to the bottom wall 131 of thecover member 130. Turning the retaining member 190 around the supportshaft 190 x can switch between the used state where the engagingprojection 191 does not engage with the movable step 42 and the retainedstate where the engaging projection 191 engages with the movable step42. However, the present disclosure is not limited to this example, andthe structure of retaining the movable step 42 by the retaining member190 may be arbitrarily changed. The position at which the retainingmember 190 is disposed may also be arbitrarily changed, for example, tothe sub-step 43 or the support bracket 45.

A technical idea that can be grasped from the above embodiment andmodified examples is as follows: A step device for a vehiclecharacterized in that a movable step includes a movable base to which asupport arm is coupled, and a resin cover that is fixed to the movablebase to be a step surface, and in that a ridge is provided on a lowersurface of the resin cover and protrudes toward a lower surface side ofthe movable step through a hole provided in the movable base.

This simple configuration makes it possible to impart a shock absorbingproperty and a self-lubricating property to the ridge while securing thestrength of the movable base. Thus, smoother turning of the support armcan be ensured.

What is claimed is:
 1. A step device for a vehicle, the step devicecomprising: a movable step supported under a door opening; a couplingmember that, in a state of being supported by a sliding door that opensand closes in a vehicle front-rear direction with a shifting zone in avehicle width direction, engages with the movable step to move themovable step in the vehicle width direction in conjunction with openingand closing of the sliding door; a support arm that has a firstpivot-joint point relative to a vehicle body and a second pivot-jointpoint relative to the movable step, and supports the movable step towardan upper side; and a pressure bearing member that is provided at aposition between the first pivot-joint point and the second pivot-jointpoint and bears a load of the support arm by coming into sliding contactwith the support arm.
 2. The step device according to claim 1, wherein:the support arm has a support bracket that is fixed to the vehicle bodyto form the first pivot-joint point; and the pressure bearing member isprovided on the support bracket.
 3. The step device according to claim1, further comprising a holding member that is fixed to the movable stepso as to hold, together with the movable step, the support arm at thesecond pivot-joint point, wherein the pressure bearing member isprovided on the holding member.
 4. The step device according to claim 1,wherein the pressure bearing member has a sliding contact surface thatextends in a direction intersecting the support arm.
 5. The step deviceaccording to claim 1, wherein the pressure bearing member is made of aresin having a shock absorbing property and a self-lubricating property.6. The step device according to claim 1, wherein a ridge that extends ina direction intersecting the support arm and comes into sliding contactwith the support arm is provided on a lower surface of the movable step.7. The step device according to claim 6, wherein: the movable stepincludes a movable base to which the support arm is coupled, and a resincover that is fixed to the movable base to be a step surface; and theridge is provided on a lower surface of the resin cover and protrudestoward a lower surface side of the movable step through a hole providedin the movable base.
 8. The step device according to claim 1, whereinthe support arm includes two main arms that are provided at positionsapart from each other in the vehicle front-rear direction, and a sub-armthat has a joint at which the sub-arm is bendable and that is providedat a position apart from each of the main arms.
 9. The step deviceaccording to claim 8, wherein the sub-arm is provided between the mainarms.
 10. The step device according to claim 1, further comprising astopper that restricts a movable range of the movable step by cominginto contact with the support arm.